SERVER-56268 Remove timeseriesBucketsCollectionClusterById server parameter

4 files changed, 7 insertions, 138 deletions

diff --git a/jstests/noPassthrough/timeseries_non_clustered_collmod.js b/jstests/noPassthrough/timeseries_non_clustered_collmod.js
deleted file mode 100644
index 2785ca4f436..00000000000
--- a/jstests/noPassthrough/timeseries_non_clustered_collmod.js
+++ /dev/null
@@ -1,52 +0,0 @@
-/**
- * Tests non-clustered time-series collections against collMod. Checks that changing
- * expireAfterSeconds on indexes is acceptable, but prevents changing the clustered
- * expireAfterSeconds option in the catalog.
- *
- * @tags: [
- *     requires_fcv_49,
- * ]
- */
-(function() {
-"use strict";
-
-load("jstests/core/timeseries/libs/timeseries.js");
-
-// Disable clustering by _id on time-series collections.
-const conn = MongoRunner.runMongod({setParameter: 'timeseriesBucketsCollectionClusterById=false'});
-
-if (!TimeseriesTest.timeseriesCollectionsEnabled(conn)) {
-    jsTestLog("Skipping test because the time-series collection feature flag is disabled");
-    MongoRunner.stopMongod(conn);
-    return;
-}
-
-const db = conn.getDB("test");
-const coll = db.timeseries_non_clustered_collmod;
-
-// Builds an index on control.min.time.
-const timeFieldName = 'time';
-const expireAfterSeconds = NumberLong(5);
-assert.commandWorked(db.createCollection(
-    coll.getName(),
-    {timeseries: {timeField: timeFieldName}, expireAfterSeconds: expireAfterSeconds}));
-
-let indexes = assert.commandWorked(db.runCommand({listIndexes: coll.getName()})).cursor.firstBatch;
-assert.eq(1, indexes.length);
-assert.eq(indexes[0].key, {time: 1});
-
-// Changing expireAfterSeconds on control.min.time is acceptable.
-const bucketsColl = db.getCollection('system.buckets.' + coll.getName());
-assert.commandWorked(db.runCommand({
-    collMod: bucketsColl.getName(),
-    index: {keyPattern: {"control.min.time": 1}, expireAfterSeconds: NumberLong(20)}
-}));
-
-// Changing the clustered expireAfterSeconds option in the catalog can't happen on a non-clustered
-// time-series collection.
-assert.commandFailedWithCode(
-    db.runCommand({collMod: coll.getName(), expireAfterSeconds: NumberLong(10)}),
-    ErrorCodes.InvalidOptions);
-
-MongoRunner.stopMongod(conn);
-})();
\ No newline at end of file
diff --git a/jstests/noPassthrough/timeseries_server_parameters.js b/jstests/noPassthrough/timeseries_server_parameters.js
index 760ffd429a7..6365203d3e8 100644
--- a/jstests/noPassthrough/timeseries_server_parameters.js
+++ b/jstests/noPassthrough/timeseries_server_parameters.js
@@ -12,35 +12,6 @@
 load("jstests/core/timeseries/libs/timeseries.js");
 load("jstests/noPassthrough/libs/server_parameter_helpers.js");
 
-// Test that collection clustering can be disabled on the buckets collection, and that it behaves
-// correctly in a replicated environment.
-(() => {
-    const replSet = new ReplSetTest({
-        nodes: 2,
-        nodeOptions: {setParameter: {timeseriesBucketsCollectionClusterById: false}},
-    });
-    replSet.startSet();
-    replSet.initiate();
-
-    const primary = replSet.getPrimary();
-    if (!TimeseriesTest.timeseriesCollectionsEnabled(primary)) {
-        jsTestLog("Skipping test case because time-series collections are not enabled.");
-        replSet.stopSet();
-        return;
-    }
-
-    const testDB = primary.getDB('test');
-    assert.commandWorked(testDB.createCollection('ts', {timeseries: {timeField: 'time'}}));
-    testDB.ts.insert({time: new Date()});
-
-    let res = assert.commandWorked(
-        testDB.runCommand({listCollections: 1, filter: {name: 'system.buckets.ts'}}));
-    let options = res.cursor.firstBatch[0].options;
-    assert(!options.clusteredIndex);
-
-    replSet.stopSet();
-})();
-
 // Valid parameter values are in the range [0, infinity).
 testNumericServerParameter('timeseriesBucketMaxCount',
                            true /*isStartupParameter*/,
diff --git a/src/mongo/db/catalog/create_collection.cpp b/src/mongo/db/catalog/create_collection.cpp
index b59b23bb22d..baef2264ecd 100644
--- a/src/mongo/db/catalog/create_collection.cpp
+++ b/src/mongo/db/catalog/create_collection.cpp
@@ -225,33 +225,14 @@ Status _createTimeseries(OperationContext* opCtx,
             CollectionOptions bucketsOptions = options;
             bucketsOptions.validator = validatorObj;
 
-            // If possible, cluster time-series buckets collections by _id.
-            const bool useClusteredIdIndex = gTimeseriesBucketsCollectionClusterById;
+            // Cluster time-series buckets collections by _id.
             auto expireAfterSeconds = options.expireAfterSeconds;
-            if (useClusteredIdIndex) {
-                if (expireAfterSeconds) {
-                    uassertStatusOK(
-                        index_key_validate::validateExpireAfterSeconds(*expireAfterSeconds));
-                    bucketsOptions.expireAfterSeconds = expireAfterSeconds;
-                }
-                bucketsOptions.clusteredIndex = true;
-            }
-
-            // Create a TTL index on 'control.min.[timeField]' if 'expireAfterSeconds' is provided
-            // and the collection is not clustered by _id.
-            BSONObj indexSpec;
-            std::string indexName;
-            if (expireAfterSeconds && !bucketsOptions.clusteredIndex) {
-                const std::string controlMinTimeField = str::stream()
-                    << "control.min." << options.timeseries->getTimeField();
-                indexName = controlMinTimeField + "_1";
-                indexSpec =
-                    BSON(IndexDescriptor::kIndexVersionFieldName
-                         << IndexDescriptor::kLatestIndexVersion
-                         << IndexDescriptor::kKeyPatternFieldName << BSON(controlMinTimeField << 1)
-                         << IndexDescriptor::kIndexNameFieldName << indexName
-                         << IndexDescriptor::kExpireAfterSecondsFieldName << *expireAfterSeconds);
+            if (expireAfterSeconds) {
+                uassertStatusOK(
+                    index_key_validate::validateExpireAfterSeconds(*expireAfterSeconds));
+                bucketsOptions.expireAfterSeconds = expireAfterSeconds;
             }
+            bucketsOptions.clusteredIndex = true;
 
             if (auto coll =
                     CollectionCatalog::get(opCtx)->lookupCollectionByNamespace(opCtx, bucketsNs)) {
@@ -260,39 +241,14 @@ Status _createTimeseries(OperationContext* opCtx,
                 existingBucketCollectionIsCompatible =
                     coll->getCollectionOptions().matchesStorageOptions(
                         bucketsOptions, CollatorFactoryInterface::get(opCtx->getServiceContext()));
-                if (expireAfterSeconds && !bucketsOptions.clusteredIndex) {
-                    auto indexDescriptor =
-                        coll->getIndexCatalog()->findIndexByName(opCtx, indexName, true);
-                    existingBucketCollectionIsCompatible &=
-                        indexDescriptor && indexDescriptor->infoObj().woCompare(indexSpec) == 0;
-                }
-
                 return Status(ErrorCodes::NamespaceExists,
                               str::stream() << "Bucket Collection already exists. NS: " << bucketsNs
                                             << ". UUID: " << coll->uuid());
             }
 
             // Create the buckets collection that will back the view.
-            const bool createIdIndex = !useClusteredIdIndex;
+            const bool createIdIndex = false;
             uassertStatusOK(db->userCreateNS(opCtx, bucketsNs, bucketsOptions, createIdIndex));
-
-            // Create a TTL index if 'expireAfterSeconds' is provided and the collection is not
-            // clustered by _id.
-            if (expireAfterSeconds && !useClusteredIdIndex) {
-                CollectionWriter collectionWriter(opCtx, bucketsNs);
-                auto indexBuildCoord = IndexBuildsCoordinator::get(opCtx);
-                auto fromMigrate = false;
-                try {
-                    uassertStatusOK(index_key_validate::validateIndexSpecTTL(indexSpec));
-                    indexBuildCoord->createIndexesOnEmptyCollection(
-                        opCtx, collectionWriter, {indexSpec}, fromMigrate);
-                } catch (DBException& ex) {
-                    ex.addContext(str::stream()
-                                  << "failed to create TTL index on bucket collection: "
-                                  << bucketsNs << "; index spec: " << indexSpec);
-                    return ex.toStatus();
-                }
-            }
             wuow.commit();
             return Status::OK();
         });
diff --git a/src/mongo/db/timeseries/timeseries.idl b/src/mongo/db/timeseries/timeseries.idl
index 046e7652346..c97e9cf1887 100644
--- a/src/mongo/db/timeseries/timeseries.idl
+++ b/src/mongo/db/timeseries/timeseries.idl
@@ -54,12 +54,6 @@ server_parameters:
         cpp_varname: "gTimeseriesIdleBucketExpiryMemoryUsageThreshold"
         default:  104857600 # 100MB
         validator: { gte: 1 }
-    "timeseriesBucketsCollectionClusterById":
-        description: "When true, newly-created time-series buckets collections are clustered by _id"
-        set_at: [ startup ]
-        cpp_vartype: bool
-        cpp_varname: gTimeseriesBucketsCollectionClusterById
-        default: true
 
 enums:
     BucketGranularity: